Usually, the blow-mould parts are held on blow-mould carrier shells and these carrier shells are in turn held on blow-mould carriers. When changing over to different container formats, in some cases the aforementioned carrier shells also have to be changed. This is also a laborious process.
In some known transforming devices for transforming plastic preforms into plastic containers, use is also made of so-called pressure cushions which press the two blow-mould parts against one another during the blowing process in order thus to counteract the internal pressure that occurs during the blowing process. During the blowing process, compressed air is usually applied to such pressure cushions in order to bring about this pushing-together. One problem during the process is often the return movement after the blowing process has taken place.